1. Field of the Invention
The present invention relates, in general, to refrigerators. More particularly, the invention relates to refrigerators with a set temperature restoration system after a power cutoff.
2. Description of the Prior Art
Refrigerators are known which have compartments for which a particular set temperature can be selected. For this compartment, for example, four different set temperatures can be selected, according to what is to be stored therein. Therefore, this compartment can be used as a freezer compartment, a partial freezing compartment, a chilled compartment, or a refrigeration compartment (referred to below as F-compartment, P-compartment, C-compartment and R-compartment, respectively). When the compartment is used as an F-compartment, P-compartment, C-compartment or R-compartment, the temperature within the compartment is controlled to be about -18.5.degree. C., -3.5.degree. C., -1.0.degree. C. and 3.0.degree. C., respectively, by using a temperature sensor mounted therein. A temperature detecting circuit includes the temperature sensor for detecting the compartment temperature and plural comparators for comparing the detected temperature with the set temperature. An example of such a temperature detecting circuit is disclosed in Japanese Patent Laid-Open Publication No. 57-164263, filed on Apr. 2, 1981 in the name of Noboru Nakagawa et al. The opening and closing time of a damper is regulated based on the temperature detected by the temperature sensor, and through the damper, cold air is supplied to the compartment to keep the temperature therein at an appropriate level. A conventional refrigerator having this kind of compartment is provided with four operating switches. These four operating switches enable the select compartment to be used as a F-, P-, C- or R-compartment by switching the appropriate switch to ON. These switches have contacts which mechanically maintain the position in which they are left after manual actuation, so when these switches are set to ON, the contacts are latched mechanically in the contacting state, closing the circuit. By setting them to OFF, the latch is released and the contacts are opened. Since the contacts of these switches are latched mechanically, when power is restored after it has been cut off, temperature control of the compartment in this type of refrigerator is governed by the prior state of the contacts.
Such a latching switch is, in general, more expensive and is less reliable than the mechanical latching mechanism. Therefore, because the prior art refrigerator described above uses an operating switch with latching contacts to control the temperature set for the compartment, this prior art refrigerator has a high cost and is less reliable.